6991491 has 8 divisors (see below), whose sum is σ = 10039120. Its totient is φ = 4302432.

The previous prime is 6991463. The next prime is 6991493. The reversal of 6991491 is 1941996.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6991491 - 2⁵ = 6991459 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 179269 = 6991491 / (6 + 9 + 9 + 1 + 4 + 9 + 1).

It is not an unprimeable number, because it can be changed into a prime (6991493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89596 + ... + 89673.

It is an arithmetic number, because the mean of its divisors is an integer number (1254890).

Almost surely, 2^6991491 is an apocalyptic number.

6991491 is a deficient number, since it is larger than the sum of its proper divisors (3047629).

6991491 is a wasteful number, since it uses less digits than its factorization.

6991491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179285.

The product of its digits is 17496, while the sum is 39.

The square root of 6991491 is about 2644.1427722421. The cubic root of 6991491 is about 191.2155767000.

The spelling of 6991491 in words is "six million, nine hundred ninety-one thousand, four hundred ninety-one".